Prognostic value of precipitins for working ability in dairy farmers.

In dairy farmers exposed to the microbes present in hay, precipitating antibodies against these microbes are frequently found regardless of the state of health of the farmer. The prognostic value of these antibodies for the future health and working ability of farmers was studied in a six-year follow-up survey of 292 farmers. During these six years, of the farmers aged 45-59 years in the primary survey, 14 men (22%) and 15 women (22%) had retired or changed occupation because of illness. Among the men, the presence of precipitins was negatively correlated with their working ability reported in the follow-up study. The risk of occupationally disabling respiratory disease was three times higher in men with precipitins against microbes present in mouldy hay than in precipitin-negative farmers of the same age. No similar correlation was found for women.